1. Field of the Invention
The present invention relates to the field of optical equipment, and more precisely, the invention relates to, but is not limited to, applications in motion picture production, The present invention is used to assist cameramen using a variety of camera stabilization or remote camera systems. Also, it may be used by puppeteers, directors, stunt coordinators, assistant directors, directors of photography or others. The present invention is for use by those requiring a view of a through-the-lens image while still retaining hands-free mobility with a majority of one's peripheral vision intact.
2. Description of the Prior Art and Related Information
There are numerous helmet mounted visual presentation devices which have been employed in a wide variety of applications including: military (air, land and sea), scientific research, education, computer peripheral systems, aerospace, industrial engineering, general aviation, undersea exploration, motor sports, as well as many other technical applications.
There is, however, generally only one device used in connection with motion picture production. That device is described by Garrett Brown in U.S. Pat. No. 4,017,168 to Brown, and in his U.S. Pat. No. Re. 32,213. The device disclosed in the Brown patents is a supportive peripheral viewfinder connected to a video tap camera on motion picture camera via a fiber optic cable. A major disadvantage of the Brown device is that it completely occludes the user's sighting or display eye, preventing any peripheral viewing in the display eye and grossly hampering depth perception in the non-display eye. Further, there is no described optical adjustment to attend to the problems encountered with refocusing or image size. Apparently, Brown's system requires that one eye focuses on the display while the other eye focuses on the much farther away general surroundings. This unbalanced focal relationship with unchecked binocular rivalry, discussed below, is undesirable and certainly would cause headaches and disorientation, making the device undesirable and dangerous if used while navigating in cluttered work areas. Hence, the Brown device does not address the need for a matting occlusion device for the non-display eye as is taught by the present invention because the device is sending two entirely separate images to the visual reception area in the brain.
Additionally, the Brown patents describe only a fiber optic link to the eyepiece with no accommodation for other external image sources.
Further, with the Brown device, there is no described visual enhancement in the form of a higher than transmitted image quality via additional lines of resolution.
Another shortcoming of the Brown viewfinder can be explained in terms of the mechanism and physiology of the human visual system. Each person has a binocular region with a binocular field of view, wherein the latter is defined as the entire area visible to both eyes at any instant and the former is the region where the fields of view of both eyes overlap. The view seen in the overlapping binocular region fuses into one image in the visual cortex of the brain, which includes a "projection area" in the occipital lobe of each brain hemisphere. This projection area maps out the image seen by both eyes.
But is a viewfinder is placed over one eye as in the Brown device, a phenomenon called binocular rivalry occurs. In general terms, binocular rivalry is when images from one eye alternately dominates over the images from the other. This phenomenon happens because the image in the field of view in one eye is significantly different than the field of view in the other eye, which is the case when the viewfinder is placed over one eye. To be sure, the focal plane of one eye is not the same as for the other eye since the object seen by the sighting eye is so much closer to that eye. Thus, the projection area in the brain is confused and cannot fuse the images from each eye.
There have been several types of efforts to overcome this problem, however. The simplest is to cover the nonsighting eye with an opaque patch, blocking out any visual information from entering that eye. But with the nonsighting eye completely covered, the cameramen loses a great deal of visual information as compared to an unobstructed eye.
A refinement over a simple eye patch is U.S. Pat. No. 4,729,648 to Armstrong, commercially marketed as "the Eyeopener." Armstrong discloses a rectangular-shaped partial eyeshield that blocks only a portion of the field of view of the non-sighting eye instead of covering the entire eye. Thus, when mounted on a camcorder, for example, the partial eyeshield blocks out only so much of the field of view as is seen through the sighting eye looking through the camcorder viewfinder. In this manner, the image from one eye complements the image from the other.
But the Armstrong device has its limitations. First, it uses a viewfinder that either completely or substantially obstructs the field of view out of the sighting eye; only the image produced by the viewfinder can be seen. Accordingly, the vision of the camera operator is impaired.
Second, because the viewfinder is positioned close to the sighting eye while the non-sighting eye, notwithstanding the partial eyeshield, has sufficient view of the surroundings, problems exist stemming from the eyes having to adjust to two focal planes. More specifically, although the binocular rivalry phenomenon may have been solved, the focal planes of the images seen by the non-sighting eye not blocked by the partial eyeshield versus the sighting eye looking at the viewfinder are not the same distance away. By analogy, the effect is if a person were to look at a far away object while simultaneously having an object lines up in the foreground, even through the images from each eye would fuse in the projection area, the eyes must re-focus from the close object to the distant object or vice versa. Therefore, the cameraman's eyes must constantly re-focus depending upon which object is being observed. This can become annoying to a cameraman who must constantly repeat the process to perform his job for many hours.
Other relevant art can be found in several military applications that employ specialized, head-mounted optical devices. For instance, a HUD (Heads Up Display) system used in fighter aircraft and ordinance delivery systems. But several of these devices that present visual information to the wearer in front of one or both eyes has revealed that most of these devices are prohibitively expensive and complex.
Further, they are generally designed with very specialized tasks in mind making them difficult and/or costly to adapt to motion picture work. Most of the military systems incorporate some form of projection system wherein the desired visual data is superimposed on a high tech translucent half-silvered mirror surface which mirror still transmits to the user/pilot all of the background visual information from his surroundings. For motion picture use, by comparison, such a feature would be undesirable because the cameraman would receive too much conflicting visual information and would not be able to concentrate solely on the camera image if he should so desire. Also with the prior art HUD systems, the cameraman does not have the control over contrast and brightness to the level which is demanded in motion picture applications.